'Undertaken' in the Bible

Then Abraham asked, "Since I have undertaken to speak to the Lord (although I am but dust and ashes),

Abraham said, "Since I have undertaken to speak to the Lord, what if only twenty are found there?" He replied, "I will not destroy it for the sake of the twenty."

And the Lord came to Sarah as he had said and did to her as he had undertaken.

And he said, O Lord, the God of my master Abraham, let me do well in what I have undertaken this day, and give your mercy to my master Abraham.